MEETING SUMMARY The 2019 James W. Freston Conference: Food at the Intersection of Gut Health and Disease Gerard E. Mullin,1 William D. Chey,2 Sheila E. Crowe,3 and the Freston Conference Faculty 1Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, Maryland; 2Division of Gastroenterology, Michigan Medicine, Ann Arbor, Michigan; and 3Division of Gastroenterology, Department of Medicine, University of California, San Diego, La Jolla, California he American Gastroenterology Association’s James exacerbates GERD and losing weight, even small percentages T W. Freston Conference was held August 9-10, 2019 of body weight, can improve GERD symptoms.7 in Chicago, IL. The topic “Food at the Intersection of Gut Health and Disease” was chosen owing to the mounting Eosinophilic Esophagitis: Man vs Food evidence for the role of diet in modulating gastrointestinal Evan Dellon, presented on the role of nutrition in the disorders coupled with the paucity of formal training in pathophysiology and treatment of eosinophilic esophagitis nutrition for gastroenterologists. The conference faculty was (EoE). Given the exponential increase in incidence of EoE unique by including registered dietitians who provided over the last 2 decades, environmental factors have been insight into dietary management. An R13 grant was awar- hypothesized to trigger disease development. Likely culprits ded by the National Institutes of Health (NIDDK) for young that have become ubiquitous in food manufacturing over the faculty who moderated sessions and collaborated on this last several years include antibiotics, growth hormones, meeting summary. food additives and preservatives, and pesticides. Diet interventions diminish symptoms and improve Plenary Session 1. Food Intolerances endoscopic features. An empiric elimination diet is more from the Top effective than elimination diets based on allergy testing. However, it is often prudent to send the patient to the Keynote Lecture: Personalized Nutrition: The allergist to manage atopic diseases that affect this patient Hope, the Hype, the Reality population. Along with the use of proton pump inhibitors Bibiana Garcia-Bilao presented evidence that knowledge and topical steroids, the mainstay of EoE management rests of human genetic variation can be harnessed to “person- on dietary therapy, namely the 6-food elimination diet. Di- alize” individuals’ nutrition to improve health outcomes and eticians are best suited to provide teaching to EoE patients prevent disease. She described how human genetic variation given the complexity and difficulties with operationalizing in the form of single nucleotide polymorphisms, copy 6-food elimination diet.8 number variance, deletions, and mutations can influence the effect of nutrition on health outcomes and may explain the variation observed in health outcomes across different Plenary Session 2. Effect of Food on the populations. Different polymorphisms have been implicated Function and Sensation in the GI Tract in taste preference,1 appetite cravings,2 and nutrient meta- 3 Role of Nutrients and Other Food Components bolism, These genetic variations in taste preference, Interacting in the GI Tract nutrient metabolism, and appetite likely play a role in Jan Tack discussed the role of nutrient sensing in func- shaping our nutritional intake and how it affects health tional digestive disorders. Patients with functional outcomes. They can be applied to health setting and dyspepsia (FD) frequently experience symptoms that can manipulated to improved health outcomes. include postprandial fullness, early satiety, and epigastric Diet Therapies for Gastroesophageal Reflux pain and burning that are often triggered by meal inges- 9 Disease: Do They Work? tion. In the stomach, tension-sensitive mechanoreceptors primarily mediate nutrient sensing and chemoreceptors John Pandolfino discussed the use of diet therapy in the (including taste receptors and transient receptor potential management of gastroesophageal reflux disease (GERD). voltage channels primarily mediate nutrient sensing in the Avoiding triggers foods can reduce GERD symptoms, although results vary.4 Certain foods may also relieve GERD symptoms. In a small study, fiber supplementation decreased GERD symptoms.5 Additionally, adoption of the Mediterranean diet Most current article has been linked with improved GERD symptoms, but it is fi © 2020 by the AGA Institute unclear if it is due to the presence or absence of speci c food 0016-5085/$36.00 6 items or simply weight loss associated with the diet. Obesity https://doi.org/10.1053/j.gastro.2020.03.036 Gastroenterology 2020;159:20–25 MEETING SUMMARY intestine.10 Differences in nutrient sensing via gastric Plenary Session 4. Role of Foods in mechanoreceptors, and intestinal chemoreceptors play a contributing role in development of symptoms in FD and Irritable Bowel Syndrome and Other understanding these interactions will assist in developing Functional GI Disorders 10,11 therapeutic options for these patients. Natural products Functional Foods and Dietary Supplements: The seem to modulate the pathophysiology and symptoms of FD Good, The Bad, and The Ugly by acting through transient receptor potential voltage Gerard Mullin presented on functional foods and dietary channels (ie, capsaicin, eucalyptol, camphor, etc). supplements. Approximately 80% of gastroenterologists – reported familiarity with complementary and alternative Gastroparesis and FD The Same or Different? medicine therapies, but rarely recommend their use.18 To Linda Nguyen reviewed the similarities and differences date, most complementary and alternative medicine studies between FD and gastroparesis. The symptoms and patho- for treatment of irritable bowel syndrome (IBS) symptoms physiology of both FD and gastroparesis have significant fi 9 have focused on ber/psyllium, probiotics, and peppermint overlap. Additionally, there are several types of gastric oil.19 Certain probiotics may be beneficial in reducing IBS neuromuscular dysfunction that can lead to the symptoms of symptoms; however, the quality of evidence is low. Meta- either FD or gastroparesis, including impaired gastric accom- analyses have demonstrated fiber and peppermint oil are modation, antral hypomotility, pylorspasm, gastric arrhyth- 20 12 effective at reducing IBS symptoms. Iberogast and herbal mias, and visceral hypersensitivity. These abnormalities may preparations with caraway improve IBS and FD symptoms. fi give rise to speci c GI symptoms, but may or may not affect Capsaicin supplementation as part of a desensitization gastric emptying as currently measured. Although the overlap protocol has been shown to decrease heartburn and FD in symptoms and pathophysiology can result in some degree symptoms. Rikkunshito (TJ-43) is an herbal supplement that of complexity when managing patients, there are similarities in is widely used in Japan and has been shown to promote treatment for both disorders, including diet modification, 12 gastric emptying and decrease FD symptoms. Mullin high- neuromodulators, and prokinetics. lighted the difference between dietary supplements (no US Food and Drug Administration [FDA] regulation), FDA Plenary Session 3. Food Allergy and regulated medical foods (FDA regulated and require clinical study evidence), and FDA-approved drugs (FDA regulated Pseudoallergy 21 and require phase I–III studies). Many Tests for Food Allergies, But Many Are Not Helpful Sheila Crowe reviewed food allergies, celiac disease, food Evidence-Based Diet Therapies for IBS: Which 13,14 intolerance, and sensitivity. This has led to more Ones for Which Patients? fi research to nd biomarkers for nonceliac gluten sensitivity, William Chey discussed evidence-based diet therapies fi health screening, gut health pro ling, intestinal antigen for IBS. Chey highlighted that >70% of patients report permeability screening, and various stool panels. These tests changing their diet owing to bowel symptoms. Despite are often directly marketed to the consumers without frequent implementation of a gluten-free diet (GFD) by pa- proper clinical validation and can be overwhelming and tients with IBS, a meta-analysis including 2 randomized, misleading for patients. When a patient presents to a controlled trials did not provide sufficient evidence to gastroenterologist for a consultation, they often have recommend a GFD for IBS.22 Despite gluten being self- already undergone one of these tests and seek advice on identified by patients as a trigger, fructan consumption what to do about the results. GI physicians will increasingly has been shown to cause increased IBS symptoms more fi need to understand the scienti c validity of these tests and than gluten in patients with nonceliac wheat intolerance. help patients to identify the best path forward. There is also growing evidence regarding the pathophysi- ology of food-associated symptoms. For example, confocal Mast Cell Activation Syndrome laser endomicroscopy of the duodenum in patients with IBS Matthew Hamilton presented a state-of-the-art lecture on has identified changes in intraepithelial gaps and compro- mast cell activation syndrome, a condition in which overly mised enterocyte integrity after exposure to food antigen reactive mast cells can trigger anaphylaxis like attacks.15 Afew challenges.23 known triggers for exacerbation of mast cell activation were There is growing evidence for use of the low FODMAPs described as well as key physical findings including derma- diet for the treatment of IBS